Then Jesus said to those Jews who believed Him, 'If you abide in My word, you are My disciples indeed. And you shall know the truth, and the truth shall make you free.' (John 8:31-32)
Presently in the United States, there is a projected belief that there is no such thing as an absolute truth. So it is not surprising to hear people challenge the idea of "The Truth" and "The Authority" of God and Christ in life. Often, people will say, "How can any church know the truth? We might all know SOME of the truth, but no one can know ALL of the truth. In fact, to say you know the whole truth is pretty arrogant." As Lutherans, we confess that what we believe and teach IS the whole truth of Christ. How can we dare say that? Because of the words above. Jesus doesn't say, "You'll know SOME truth" but "THE Truth" and it will set us free.
What is the truth? It is Jesus. Jesus, who is true God and true man. Jesus, who was born of the Virgin Mary. Jesus, who was baptized for sinners. Jesus, who preached and taught that salvation is in Him. Jesus healed the sick in His perfect compassion and love. In so doing, the recipients of His healing and the witnesses then and now (through the Bible), would recognize Jesus as the Savior. As God proclaims in John 10:38-39, 38. But if I do it, even though you do not believe me, believe the miracles, that you may know and understand that the Father is in me, and I in the Father." Jesus, who was arrested, beaten, tried, flogged and nailed to the cross for the sins of the whole world. Jesus, who rose from the dead. Jesus, who ascended and will come again. This Jesus is THE Truth.
But, He does not give us that truth just out of nowhere, nor does God turn us loose in His Word and leave us to figure it out without His guidance. God gives His Word and His Holy Spirit continues to work with and through the Word/Scripture/Bible to guide us to all truth. Jesus promised to send His Spirit; Jesus speaks of this truth in John 15:26-27, "When the Counselor comes, whom I will send to you from the Father, the Spirit of truth who goes out from the Father, he will testify about me. 27. And you also must testify, for you have been with me from the beginning." It comes to us through the faithful preaching of Jesus and the giving of the gifts which He Himself commanded. Truth comes to us in Holy Baptism by water and the Word, in Absolution, and in the Lord's Supper. There Christ comes to us, delivering His truth, the forgiveness of sins and setting us free.
Those who say that you can't know all the truth, deny Jesus's words. To say that we can't know all the truth or be truly certain about God or what He's done for us is calling God Himself a liar. Jesus came to save us. He didn't come to hide it or give it out a bit at a time, but to accomplish all of our salvation totally and completely and to give us that salvation with nothing else needed. In Christ, we have all that we need for this life and the life to come. In Christ, we have the Truth for all the world to see, the saving truth which rescues us from darkness and gives us freedom from sin and true and eternal life.